Department of Immunohematology and Blood Transfusion, Leiden University Medical Centre, Leiden, The Netherlands.
Transplantation. 2011 Mar 15;91(5):494-500. doi: 10.1097/TP.0b013e318207944c.
The crossreactivity of Epstein-Barr virus (EBV Epstein-Barr virus nuclear antigen 3A [EBNA3A])-specific CD8 T cells against allogeneic human leukocyte antigen (HLA)-B44:02 has been shown to be dependent on presentation of self-peptide EEYLQAFTY by the target antigen. In this study, we report that allogeneic HLA-B44:02 proximal tubular epithelial cells (PTECs) and human umbilical vein endothelial cells (HUVECs) are poor targets for EBV EBNA3A-specific T cells.
The EEY peptide was exogenously loaded onto HLA-B44:02 and HLA-B44:03-expressing PTECs and HUVECs. EEY-peptide-loaded, and unloaded, PTECs and HUVECs were then incubated with serial dilutions of our EBNA3A T-cell clone, in a cytotoxicity assay.
Although HLA-B44:02-expressing PTECs were specifically lysed in proportion to the effector/target ratio by the EBNA3A T-cell clone, without peptide loading, lysis was greatly increased by exogenous EEY peptide loading (15% vs. 75%; P<0.0001). HLA-B44:02-expressing HUVECs were only lysed when loaded with exogenous EEY peptide (0% vs. 64%; P<0.0001). Lack of HLA expression and lack of ABCD3 gene expression were excluded as a cause for these results. PTECs and HUVECs were specifically targeted by another alloreactive T-cell clone without exogenous peptide loading, suggesting that the lack of recognition of HLA-B*44:02 epithelial and endothelial cells by the EBV EBNA3A T-cell clone was due to lack of EEYLQAFTY peptide presentation.
Tissue-specific (peptide dependent) alloreactivity may have important implications for transplantation monitoring and rejection.
已证实，针对异基因人白细胞抗原（HLA）-B44:02 的 Epstein-Barr 病毒（EBV）核抗原 3A（EBNA3A）特异性 CD8 T 细胞的交叉反应性取决于靶抗原对自身肽 EEYLQAFTY 的呈递。在这项研究中，我们报告说，异基因 HLA-B44:02 近端肾小管上皮细胞（PTEC）和人脐静脉内皮细胞（HUVEC）是 EBV EBNA3A 特异性 T 细胞的较差靶标。
将 EEY 肽外源性加载到 HLA-B44:02 和 HLA-B44:03 表达的 PTEC 和 HUVEC 上。然后，将负载和未负载 EEY 肽的 PTEC 和 HUVEC 与我们的 EBNA3A T 细胞克隆的系列稀释液一起孵育，进行细胞毒性测定。
尽管在没有肽负载的情况下，HLA-B44:02 表达的 PTEC 会被 EBNA3A T 细胞克隆按比例特异性溶解，但通过外源性 EEY 肽负载，溶解率大大增加（15%对 75%；P<0.0001）。仅在外源 EEY 肽负载时，HLA-B44:02 表达的 HUVEC 才会被溶解（0%对 64%；P<0.0001）。排除了 HLA 表达缺失和 ABCD3 基因表达缺失作为导致这些结果的原因。在没有外源性肽负载的情况下，PTEC 和 HUVEC 被另一种同种反应性 T 细胞克隆特异性靶向，这表明 EBV EBNA3A T 细胞克隆对 HLA-B*44:02 上皮和内皮细胞的识别缺失是由于缺乏 EEYLQAFTY 肽呈递所致。
组织特异性（肽依赖性）同种反应性可能对移植监测和排斥反应具有重要意义。
